Microsoft has finally begun its road to commercial availability of its next Windows 10 feature update, the May 2020 Update, which also is known as Windows 10 2004. Today, May 12, Microsoft made Windows 10 2004 available to developers via MSDN today, May 12.

The Windows team has been following this phased approach of delivering a new feature update to OEMs, then developers and finally to mainstream users, for the past few releases. Today, Microsoft is making available the software development kit for Windows 10 2004 under a go-live license and has released the update to those with access to MSDN. Microsoft is advising developers to use the Windows 10 Release Preview ring version of 2004 to update their development environments for now, however.

Microsoft hasn’t been in a hurry to roll out 2004, given the many work and home disruptions resulting from the COVID-19 coronavirus pandemic. The product has been basically “done” for a while and Microsoft has continued to issue cumulative updates for it to testers across its various “rings” — including yet another cumulative update for it today for Slow and Release Preview testers.

After deciding to squeeze in one more fix before releasing the update, Microsoft pushed back its planned timetable for its Windows 10 2004 release, which called for it to begin rolling out to the mainstream on May 12, my contacts said.

My sources said that Microsoft delivered Windows 10 2004 to its PC OEM partners last week. I’ve heard the rollout to mainstream users will likely commence on May 28. I’ve asked Microsoft for confirmation on the rollout schedule, but received no word back.

Windows 10 2004 includes a lot of fixes and updates, plus a handful of noteworthy new features. This is the update which adds Windows Subsystem for Linux (WSL) 2 support to the OS. (Don’t forget about Microsoft’s decision to remove the Linux kernel from the OS image back in March.) It also includes an option to download setup files from the cloud, instead of using local installation files. Windows 10 2004 adds an option to automatically restore open apps after a restart, as well.

Microsoft already has been testing via the Fast Ring new features which may or may not end up in Windows 10 20H2. My sources have said that Microsoft is planning to make the 20H2 build a small, incremental update to 2004 — the same way that 1909 was a cumulative-update-like experience to 1903. Microsoft officials have not said this publicly, however.